The ISynchronizeInvoke interface provides synchronous and asynchronous communication between objects about the occurrence of an event. Objects that implement this interface can receive notification that an event has occurred, and they can respond to queries about the event. In this way, clients can ensure that one request has been processed before they submit a subsequent request that depends on completion of the first.

Synchronously, by using the Invoke method. Invoke starts a process, waits until it completes, and then returns. Use Invoke when the control's main thread is different from the calling thread to marshal the call to the proper thread.